Unwanted AC voltage on pipelines can create both a safety hazard and damage to the pipeline from AC corrosion. AC voltage mitigation systems have been developed that ground the pipeline at appropriate locations to ensure both steady-state and fault-related AC voltages are maintained at safe levels. One of the greatest challenges with these systems is to provide effective earthing without negatively affecting the cathodic protection (CP) system used for corrosion management on the pipeline. Without properly isolating the CP system from the earthing system, pipeline operators will likely find it difficult to maintain adequate CP potentials.
Decouplers provide effective DC isolation of cathodically protected structures from other objects or earthing systems while maintaining AC continuity for both steady-state and fault-related sources and lightning. Having these features, decouplers play a key role in the overall effectiveness of AC Voltage Mitigation systems.
This webinar will provide a brief overview of the mechanisms of AC interference on pipelines, common methods employed for AC voltage mitigation, and a brief description of solid-state decouplers and their operation. In addition, key guidelines for applying decouplers with AC mitigation systems will be discussed, including the influence of grounding materials, decoupler ratings, the effects of decoupler capacitance on interrupted surveys, and available solutions.
Expect to learn:
- A basic introduction to AC interference on pipelines, including:
- Sources of AC interference
- AC corrosion
- Conformance criteria
- The key role of DC decouplers in AC mitigation systems
- Guidelines for the application of DC decouplers, i.e.,
- Influence of grounding materials
- Decoupler ratings
- Effects of decoupler capacitance on interrupted surveys
- Available solutions